This invention relates to shock mounts for devices that may be packaged in portable cartridges, and, more particularly, to portable cartridges that are potentially subject to rough handling, such as cartridges employed for the storage of data. In one embodiment, the device comprises a magnetic disk drive assembly.
Portable data storage cartridges typically comprise a data storage media, such as magnetic tape, which are inserted into a separate data storage drive so that data may be read and/or written on the data storage media. Such cartridges are convenient means of storing large quantities of data which are accessed occasionally. They are particularly useful in automated data storage libraries which can contain large numbers of the cartridges on storage shelves and employ a robot accessor to access a cartridge when needed and deliver the cartridge to a data storage drive. Copending and coassigned U.S. patent applications Ser. No. (TUC920000060) and Ser. No. (TUC920010002), describe such data storage cartridges, but which contain devices such as data storage drives, and describe transfer stations for reading and/or writing data, and for supplying power, with respect to the data storage drives.
In handling the cartridges, robot accessors of automated data storage libraries occasionally drop a cartridge, or misplace a cartridge such that it is handled roughly, and manual handling is also likely to result in an occasional dropped or roughly handled cartridge.
Further, a requirement of any data storage device that is to be packaged in a cartridge is that it be small in size (so as to fit within the cartridge); and another requirement is that it have a large data storage capacity (so as to be useful). Data storage devices designed for use in portable computers typically meet these requirements. However, the cartridges are typically subject to rough handling far greater than that of a portable computer.
An example of a data storage device is a magnetic disk drive assembly, which is encased, self-contained and operational, comprising both the necessary mechanical and electronic components. A typical encased magnetic disk drive assembly comprises at least one rotatable disk, a motor for rotating the disk(s), at least one head, an actuator and servo system for seeking and tracking, and addressing, motor control and data handling electronics for reading and writing data, and for communicating at the data transfer interface, for example, employing an industry standard format, such as IDE, SCSI or PCI. The assembly is typically encased to prevent debris from getting into the assembly. The height dimension, comprising the stack of heads, one or more disks, and the disk motor, is typically the most critical, such that there is no room for a support structure for the cover over the disks and heads. Any force exerted on the cover has the possibility of causing the cover to deflect inwardly such that it may contact a head or disk, destroying or causing damage to the disk drive. The case typically has a breathing hole to prevent atmospheric pressure variations from deflecting the cover. An organic filter and a desiccant may be provided on the inside of the hole for filtering debris and contaminants. As the result, although shock absorption is necessary, the cover comprises a sensitive surface which is unable to support a shock absorbing structure. Similarly, the typical magnetic disk drive assembly has a PCB at the bottom surface, which also comprises a sensitive surface that is unable to support a shock absorbing structure without deflecting and damaging the drive. Thus, such sensitive surfaces may be unable to come into contact with a shock absorbing structure without causing damage to the disk drive, and certainly would be unable to come into contact with the cartridge shell, for example, through slippage within the shock mount, without causing damage to the disk drive.
U.S. Pat. No. 6,154,360 describes an impact resistant storage subsystem having a middle pad surrounding the periphery of a data storage device to provide lateral support. Brackets may be added at the outside of the device to expand the size of a small form factor drive to fit the cavity in the middle pad. Upper and lower pads have cavities to provide vertilation to the drive and provide vertical support to the drive at its periphery or at the brackets. When subjected to shock impact in a lateral direction, the middle pad will compress and may allow the drive to slip such that the opposite edge of the drive enters the ventilation cavity of the upper or lower pad, trapping the drive so that it cannot return to the original position. In a subsequent impact, the drive is likely to slap against a housing supporting the pads.
An object of the present invention is to facilitate shock absorption with respect to a device having at least one attachment point, while avoiding contact with a sensitive surface.
Another object of the present invention is to prevent slippage of the drive in the shock mount, so that the drive may be protected against subsequent shocks.
In one embodiment, a shock mount structure is disclosed for facilitating shock absorption with respect to a device having at least one attachment point, the shock mount structure comprising wing-like outriggers mounted to the device at the attachment point, the outriggers positioned between two contacting force absorption members, distributing shock force of at least one direction to the force absorption members, and supporting the device against slippage with respect to the force absorption members in that direction. The direction is preferably selected to be normal to that of any sensitive surface and thereby allow the force absorption members to avoid contact with the sensitive surface.
As an example, first and second wing-like outriggers are mounted to the device at the attachment point(s), such that the second outrigger is located at a diametrically opposite side of the device from the first outrigger. Thus, the first and second outriggers distribute a shock force normal-to the sensitive surface, generally balanced at either side of the device, to the force absorption members, and support both sides of the device against slippage with respect to the force absorption members in that direction.
In another embodiment, a force absorption member comprises an inner element and an outer element, each of foam materials, the inner element of greater density than the outer element, the inner element in contact with the outrigger(s).
In a further embodiment, leaf spring tabs are formed within the cartridge shell, spaced from an edge of the cartridge shell to allow flexure of the leaf spring tabs. The force absorption member is positioned between the device and the leaf spring tabs, and in contact with the leaf spring tabs, such that the leaf spring tabs assist in absorbing shock force of a direction normal to the leaf spring tabs.